The present invention relates to a process for the production of acidified meats useful in the preparation of acidified foods.
Canned foods are presently heat processed in a retort to prevent microbiological spoilage at room temperature. These products are processed to a point of "commercial sterility", which is defined in 21 CFR 113.3(e), as a condition achieved by the application of heat which renders the food free of microorganisms capable of reproducing in the food under normal, nonrefrigerated conditions of storage and distribution and viable microorganisms, including spores, of public health significance. This degree of sterility is attained when all pathogenic and toxin-forming organisms have been destroyed as well as resistant types which, at present, could grow in the product and produce spoilage under normal conditions.
Retorting of canned products is in effect a double cooking that can have a serious effect on the texture and quality of the product. Macaroni-type products, upon retorting, attain a mushy or soft appearance and mouth-feel which is organoleptically unsatisfying.
Commercial sterility of canned-food products can also be obtained by mild heat treatment at pH's of 4.6 or below. As stated in 21 CFR 114.3(b), acidified foods are defined as those acid foods or foods to which acid is added, which have a water activity (a.sub.w) greater than 0.85 and finished equilibrium pH of 4.6 or below. Acid foods can contain small amounts of low acid foods (a pH greater than 4.6 and a water activity greater than 0.85) and have resultant finished equilibrium pH that does not significantly differ from that of the predominant acid or food product. To insure that no pockets of viable bacteria remain after processing, the pH must be uniformly reduced below 4.7 prior to cooking even in the interior of large particles such as meat.
The growth of toxin-forming microorganisms, such as Clostridium botulinum, can be inhibited by mildly heating foods having a pH of 4.6 or less or extensively heating foods having a pH above pH 4.6. Foods having a pH above 4.6 require high processing temperatures of about 115.degree. C. for prolonged periods of time in order to assure adequate destruction of the microorganisms.
In an attempt to avoid the extensive retorting of products that seriously affects the color, texture and flavor, foods can be acid blanched to reduce the overall pH of the food (U.S. Pat. No. 3,886,296). This acid blanch can be used for a number of foods to lower the pH and, thereby, reduce the necessity of extensive retort time. However, U.S. Pat. No. 3,886,296 teaches that meat, in the form of meatballs, may be included in a tomato-sauce product by sterilizing the meatballs by steam cooking at 121.degree. C. for 15 minutes. After sterilization, the meatballs can be then added to a heated sauce and an acid blanched pasta. The avoidance of the use of the acid blanch technique for ground meat products in U.S. Pat. No. 3,886,296 is in line with the fact that ground meat emulsions lose their binding ability when treated with acid. Acid blanching would thus destroy the character of the meatballs. Acid blanching cannot be used for larger particles as sufficient reduction in the interior pH cannot be achieved. At present, meatballs for low acid foods are prepared by the use of encapsulated acids or acidogens which do not release the acid until the meat is heated sufficiently to denature the protein (U.S. Pat. No. 3,359,120). In addition to the added expense of the encapsulated acid, it has been found that a portion of acid is released simply by contact with cold water. Meat processors using fat-coated acids have noted problems with shorting-out of the emulsion prior to cooking. This leads to the breakdown of the meatballs and the formation of fine meat particles and free fat which are unsightly in the product.
Presently, small particles of meat which are being added to acidified tomato sauce products are prepared by extrusion and cutting. The product has the appearance of pellets and not naturally browned meat as prepared in a kitchen. It would be desirable to provide meat particles which had the proper interior pH and the appearance of kitchen-browned meat.